This relates generally to real-time data acquisition, and more particularly to real-time data acquisition using chained direct memory access (DMA) channels.
In many embedded system applications, the acquisition of data from an analog-to-digital converter (ADC) or similar device via a peripheral such as a serial port interface (SPI) is performed in synchronization with an external event. In some applications, a dedicated processor such as a microcontroller or a digital signal processor is used for the data acquisition to achieve real-time performance. In other applications, the data acquisition is software-based and executes on a processor that is also executing the operating system and performing other tasks. In such applications, the data acquisition is typically interrupt driven, and as such, the performance is non-deterministic due to varying interrupt latencies caused by factors such as other tasks/servers/services executing in the system, drivers that may disable interrupts, and the speed of the processor.